As is well known and understood, when a truck tractor or truck unit breaks down on the road, a "wrecker" vehicle is oftentimes dispatched to bring it to a location where it can be serviced. In other instances, a second tractor might be dispatched, along with a "long-bed" trailer, onto which the disabled tractor or truck unit is brought, for bringing to the servicing location. This type of "wrecker" and "long-bed" trailer equipments are employed not only where there might be an engine malfunction in the truck tractor or truck unit, but in a wide range of situations where the truck tractor, or truck unit, cannot simply be driven away--as, for example, where the vehicle has been involved in an accident, causing damage to its wheels or under-carriage.
While quite appropriate for their purposes, several disadvantages follow in having to use these equipments, to begin with. For example, in order to handle such sizes as are encountered with truck tractors and truck units, the automotive "wrecker" must be a heavy-duty unit--which, by definition, makes the "wrecker" quite expensive to purchase, and attendant with high registration and insurance costs. Damage, furthermore, often follows from the use of the hooks and chains of the "wrecker", in towing about the disabled vehicle. And, whereas just about all States permit a "wrecker" to drive onto a turnpike, thruway or freeway to pick up a disabled vehicle, many States do not permit a "wrecker" to enter onto such high speed roadway if already having a vehicle in tow.
As to the "long-bed" trailer, on the other hand, one of its major drawbacks follows from its size--namely, it generally requires a two-man operation, one to drive the vehicle onto the trailer, and a second, to guide the first in getting the vehicle up (or down) the ramps utilized. (Also, because such ramps as are employed are most frequently made of steel or other weight-sustaining material, at least two men are required just to lift the ramps and to align them in place.) A second disadvantage in using this type of apparatus is that the under-carriage and wheels of the truck tractor or truck unit must be operational, in order that the vehicle can be driven up onto the "long-bed" trailer to begin with--a requirement which is not necessary if "wrecker-towing" were employed. With these types of "long-bed" trailers being generally of the order of 35 feet in length, furthermore, such units (like the "wrecker") can also tend to be quite costly.